A much publicized 1955 report on artery plaques in soldiers killed during the Korean War showed high levels of atherosclerosis, but another report—one that did not make it to the front pages—found that Japanese natives had almost as much pathogenic plaque—65% versus 75%—even though the Japanese diet at the time was lower in animal products and fat.4

A 1957 study of the largely vegetarian Bantu found that they had as much atheroma—occlusions or plaque buildup in the arteries—as other races from South Africa who ate more meat.5

A 1958 report noted that Jamaican Blacks showed a degree of atherosclerosis comparable to that found in the United States, although they suffered from lower rates of heart disease.6

A 1960 report noted that the severity of atherosclerotic lesions in Japan approached that of the United States.7

The 1968 International Atherosclerosis Project, in which over 22,000 corpses in 14 nations were cut open and examined for plaques in the arteries, showed the same degree of atheroma in all parts of the world—in populations that consumed large amounts of fatty animal products and those that were largely vegetarian, and in populations that suffered from a great deal of heart disease and in populations that had very little or none at all.8

All of these studies pointed to the fact that the thickening of the arterial walls is a natural, unavoidable process. The lipid hypothesis did not hold up to these population studies, nor did it explain the tendency to fatal clots that caused myocardial infarction.